I'm a big advocate of the phrase, "Release Early, Release Often." I think it is by far the best way to keep or gain community interest in a project.
Of course, that simple phrase doesn't quite sum up what you actually must do - simply uploading a release and announcing it on your mailing list is unlikely to attract interest. For example, who knew about Lincity-NG 2.9beta in lieu of the intended Lincity-NG 3.0?
Lincity-NG is in a bit of a mini-crisis. A victim of the shutdown of the Berlios developer services, all the web material is in a bit of a mess. Its home page is now on fedorahosted.org but still links back to the defunct Berlios page. There are entries on Google Code and Github that are up to date with the source, as well as an imported Sourceforge project* which is the only place you can currently find the beta, however all are unofficial / back up for now.
(* Not to be confused with this redundant redundant project)
Another game project which suffered was Battles of Antargis. It has re-emerged on Github and development seems to have resumed with C++ replacing the Ruby bits which previously encumbered the game. For a web presence, you have to use the Internet archive for its old Berlios page or external sites e.g. the LGBD entry or on Libregamewiki.
|Battles of Antargis|
Since there doesn't appear to be any project communication channel for ETR, I have contacted them suggesting a FreeGameDev forum.
Speaking of FGD forums, there's plenty of activity amongst the projects there. Stunt Rally continues to gain more strings to its bow. Sci-fi hovercrafts! That ought to be interesting. Despite being one of the prettiest open source games and incredibly put together almost by one person, CryHam - well, not quite; it took VDrift's physics and Ogre3D's jazz - the project doesn't seem to get the attention it deserves.
|Sci-fi overcrafts now in Stunty Rally|
Another project gaining momentum is OpenDungeons. It's had its ups and downs, but seems to have gotten its footing now with regular test releases and several active contributors. The new website is coming along, but more importantly so is the game as especially Yohann Ferreira aka Bertram (of Valyria Tear fame) has come in and steadied the ship. I look forward to seeing creatures like this golem trudging dark, damp and dangerous dungeon corridors.
Of course the reality of open source game development is that it is not an overnight job. It takes years of perseverance to realise the goals of many projects. Over the course of that time, occasionally the rug may get pulled from under you. You just have to be prepared to dust yourself off, get up, and keep going.
Or you could just call it quits.